Circuit breaker accessories have found increasingly wide application as derivatives from and complements to the functionality of a circuit breaker. One example of a circuit breaker accessory is the breaker locking device, which can be used for locking the circuit breaker in a trip condition or an “OFF” condition when the circuit on the load side of the breaker needs servicing or when it is not allowed to switch on the circuit, so as to prevent the breaker from being turned “ON” by accident, thereby the safety of the service man or the reliable operation of the electric appliance can be ensured.
Currently a circuit breaker equipped with a locking device is seldom seen on the market, and usually the locking device is additionally attached to the circuit breaker at the request of the customer. Typically, the locking device is mounted on the primary cover of the circuit breaker, and for properly fixing the locking device, it may be necessary to specially design the primary cover. Thus, two different sets of molds for molding the primary cover may have to be prepared, respectively for producing a primary cover for a breaker without a locking device and a primary cover for a breaker with a locking device. In this case, the costs involving in the design and production of the primary cover will increase, and the stocks for the two different kinds of primary covers will also increase. In addition, the prior art locking device for a circuit breaker is relatively complicated in structure, and not easy to install and fix.
The invention aims to solve the problems set forth above, that is, to provide a circuit breaker having a locking device that is simple in structure, easy to install and low in cost.